Même problème ici 
Hi, just adding that I’m also experiencing this issue.
When exporting Looker Studio reports as PDF, an extra blank space appears at the top of each page. This shifts all content downward and causes parts of the report to get cut off at the bottom, making the exported output unreadable.
This seems to happen consistently across multiple reports. The layout looks correct in edit/view mode, but the issue appears only in the exported PDF.
Hope this helps confirm the issue.
Hi all,
This issue has been fixed now. Thank you for your patience.
Thanks,
Maaz (Data Studio Team)
I was having very similar issues with this, except I was getting a partial duplicate of the first, prior page, showing up, totally cut off and with the wrong sizing.
To fix it, I moved all my hidden pages, or pages with custom view permissions to the end of the report, and the seems to have solved the problem.